Characterization, diversity, and relationships of the Spanish striped (Listada) eggplants: a model for the enhancement and protection of local heirlooms

Spanish striped eggplants (Solanum melongena L.) are generally known as Listada. Among them, the most internationally renowned is the Listada de Gandía heirloom. Enhancement and legal protection of these local materials requires the analysis of their characteristics, diversity and relationships with similar accessions. We performed a morphological, agronomic and molecular (amplified fragment length polymorphism; AFLP) characterization of 33 eggplant accessions, which included 20 Striped accessions, of which nine were Spanish (five Listada de Gandía and four of Other Spanish Listada), 11 non-Spanish (six of Non-Spanish Listada and five of Other Non-Spanish Striped) and 13 Non-Striped accessions. The Striped accessions presented a range of morphological, agronomic and genetic diversity comparable to the one observed in the Non-Striped accessions. Multivariate PCA (morphological) and PCoA (molecular) analyzes group together the Listada accessions, and clearly separate the three Listada subgroups (Listada de Gandía, Other Spanish Listada and Non-Spanish Listada). On the other hand, the Other Non-Spanish Striped accessions are closer to Non-Striped than to Listada accessions. Listada eggplants, as well as each of their subgroups, are characterized by a syndrome of morphological traits that allows distinguishing them from other accessions. Furthermore, AFLP markers which allow distinguishing Listada accessions and the Listada de Gandía heirloom have been found. The agronomic characterization shows that despite the low diversity within Listada de Gandía group, it is possible to select accessions with improved agronomic performance. The results obtained have important implications for the conservation, improvement and legal protection of Spanish striped eggplants, and in particular of the Listada de Gandía heirloom. The methodology and approaches used may provide a model for the enhancement and protection of other vegetable crops heirlooms.